1. Field of Invention
The present invention relates to equipment for establishing video communication via a computer screen. More particularly, the present invention relates to equipment that utilizes the telephone network to output video images on a computer screen and achieves dynamic video and voice communication through a computer system.
2. Description of Related Art
In the past few decades, development in electronic technologies is so fast that people can now routinely communicate with each other through an electronic media. Recently, the communication media has gone a step forward by the development of video communication techniques and equipment. Besides being able to listen to the voice coming from the other party through a telephone network, somewhat dynamic video images can be transferred through a telephone line at the same time. An example is the video teleconferencing system now widely used in a business environment. Hence, communication is going to be more life-like when the same kind of systems can be use at home using a personal computer.
FIG. 1 is a block diagram showing a conventional method for generating digital image. As shown in FIG. 1, the transmission of conventional video signals involves a camera 10. The camera 10 records an image, and then the image is passed to a microprocessor 12 where the image is converted into data with a specified digitized format. For example, the format Y:U:V=4:2:2 originated by the company AMD is now commonly used to represent digital image data Ddig. Next, the digital image data Ddig are output to the receiving side. On receiving the digital image data Ddig, the image is reproduced and displayed in a television screen. Since the output video data is suitable for television only, it is difficult to be displayed on a computer screen.
In light of the foregoing, there is a need for widening the useful range for the digital image data.